Savvas Nicolaou

Vancouver General Hospital · Department of Radiology

Dual-energy computed tomography (DECT) is an advanced imaging technique that acquires data using two distinct X-ray energy spectra, typically at 80 and 140 kVp, to differentiate materials based on their atomic number and electron density. This capability allows for the enhanced visualization of various pathologies, including bone marrow edema (BME)...

Purpose of Review The article represents the value of imaging including conventional multidetector computed tomography (MDCT) and dual-energy computed tomography (DECT) in the evaluation and diagnosis of various pathologies associated with acute abdominal pain in the elderly population. Recent Findings Advances in DECT have dramatically improved t...

Radiology in Canada is advancing through innovations in clinical practices and research methodologies. Recent developments focus on refining evidence-based practice guidelines, exploring innovative imaging techniques and enhancing diagnostic processes through artificial intelligence. Within the global radiology community, Canadian institutions play...

Acute diaphragmatic abnormalities encompass a broad variety of relatively uncommon and underdiagnosed pathologic conditions, which can be subdivided into nontraumatic and traumatic entities. Nontraumatic abnormalities range from congenital hernia to spontaneous rupture, endometriosis-related disease, infection, paralysis, eventration, and thoracoab...

Advancing medical technology revolutionizes our ability to diagnose various disease processes. Conventional Single-Energy Computed Tomography (SECT) has multiple inherent limitations for providing definite diagnoses in certain clinical contexts. Dual-Energy Computed Tomog-raphy (DECT) has been in use since 2006 and has constantly evolved providing...

Objective There is surging interest in using dual‐energy computed tomography (DECT) to identify cardiovascular monosodium urate (MSU) deposits in patients with gout. We sought to examine the prevalence and characterization of cardiovascular DECT artifacts using non–electrocardiogram (EKG)‐gated DECT pulmonary angiograms. Methods We retrospectively...

Retained needle fragments commonly serve as sources of recurrent infections with a potential to embolize to the heart and lungs and can lead to life-threatening consequences. Here, we report a case of a 46-year-old male with a history of intravenous drug user and chronic forearm wounds, presenting with sepsis. Several retained needles are identifie...

The liver, spleen, and kidneys are the commonest injured solid organs in blunt and penetrating trauma. The American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) is the most widely accepted system for categorizing traumatic injuries. Grading systems allow clear communication of findings between clinical teams and assign a me...

Breast injury is commonly encountered yet it remains significantly underreported. Injury to the breast may arise from either primary mechanisms or secondary or iatrogenic mechanisms. Primary mechanisms of breast injury include blunt force, seat-belt, penetrating, and thermal injury. Secondary or iatrogenic mechanisms of breast injury include breast...

Gastropulmonary fistula represents a late complication of sleeve gastrectomy and, if untreated, has high morbidity and mortality. We present a case report of a 29-year-old female who developed a gastropulmonary fistula 3 years after a sleeve gastrectomy. Dual energy CT of the chest and upper abdomen demonstrated a cavitary left lower lobe lesion as...

AI has the ability to support the radiologist far beyond the process of image analysis. AI can be utilized to enhance efficiency at all stages of radiology workflow by assisting in an array of non‐diagnostic and repetitive tasks – for example, resource allocation, support for imaging order entry, patient scheduling, and improving the radiology work...

With the introduction of convolutional neural networks, radiological image acquisition could shift from physics‐based image reconstruction and image optimization algorithms to neural network–based ones. This is poised to help reduce radiation dose, improve image acquisition times, decrease imaging instrument costs, and improve contrast safety while...

AI in radiology is unique compared to other clinical specialties in the sense that there already exists a large marketplace with commercially available, Food and Drug Administration–approved solutions. In this chapter, we will introduce the reader to the current AI in radiology offerings, and touch on future areas that may have high impact on patie...

Establishing an emergency radiology division in a practice that has long-standing patterns of operational routines comes with both challenges and opportunities. In this article, considerations around scheduling and staffing, compensation, and equity and parity are provided with supporting literature references. Furthermore, a panel of experts havin...

We describe a case of chronic tophaceous gout affecting the spine, hands, elbows, feet, and knees in a 67-year-old man with serum urate levels at 549 µmol/L whose response to treatment was successfully mapped using dual-energy computed tomography (DECT). The patient presented with exacerbation of acute-on-chronic lumbar back pain. He had received a...

Purpose To develop and assess the performance of a machine learning model which screens chest radiographs for 14 labels, and to determine whether fine-tuning the model on local data improves its performance. Generalizability at different institutions has been an obstacle to machine learning model implementation. We hypothesized that the performance...

Objective: To identify magnetic resonance imaging (MRI) predictors (cartilage [C], osteophytes [O] and meniscus [M] scores) of prevalent and 3-year incident medial tibiofemoral (MTF) and lateral tibiofemoral (LTF) knee joint tenderness and patellofemoral (PF) grind. METHODS: Population-based knee pain cohort aged 40-79 was assessed at baseline (N...

Background To evaluate the effect of statin use on osteoarthritis (OA) incidence/progression using magnetic resonance imaging (MRI) in a population-based cohort with predominantly pre-radiographic knee OA. Methods A cohort aged 40–79 years with knee pain was recruited using random population sampling and followed for 7 years. Baseline exclusions w...

Purpose: To assess value of dual energy computed tomography (DECT) collagen material decomposition algorithm when combined with standard computed tomography (CT) in detection of lumbar disc extrusion and sequestration. Materials and Methods: Retrospective analysis of all patients with acute low back pain who had a diagnosis of lumbar spine disc ext...

Emergency Radiology is a clinical practice and an academic discipline that has rapidly gained increasing global recognition among radiology and emergency/critical care departments and trauma services around the world. As with other subspecialties, Emergency Radiology practice has a unique scope and purpose and presents with its own unique challenge...

Traumatic bowel and mesenteric injuries (TBMI) have significant morbidity and mortality. The physical examination is often limited and sometimes not feasible in the trauma patient. Multidetector CT (MDCT) detection of TBMI is challenging and can be life-saving. Dual-energy CT (DECT) utilizes iodine overlay, monoenergetic imaging, and metal artifact...

Rationale and Objectives Hard data labels for automated algorithm training are binary and cannot incorporate uncertainty between labels. We proposed and evaluated a soft labeling methodology to quantify opacification and percent well-aerated lung (%WAL) on chest CT, that considers uncertainty in segmenting pulmonary opacifications and reduces label...

Acute abdominal and pelvic pain can have a wide range of etiologies, from self-limiting conditions to acute pathologies requiring emergent surgery. Emergency radiology plays a pivotal role in the routine diagnosis and outcomes of patients with these disorders. Computed tomography (CT) with evolved protocols and technological advancements in particu...

Purpose: Cardiac computed tomography angiography (CCTA) is increasingly used for device surveillance after left atrial appendage closure (LAAC). While CT protocols with delayed scans are useful to diagnose thrombus in the LAA, an optimal protocol for post-procedural CCTA has not been established. Therefore, we assessed the role of delayed versus e...

Disaster planning is a core facet of modern health care practice. Owing to complex infrastructure requirements, radiology departments are vulnerable to system failures that may occur in isolation or during a disaster event when the urgency for and volume of imaging examinations increases. Planning for systems failures helps ensure continuity of ser...

Objective To develop a whole-joint, unidimensional, irreversible, and fine-grained MRI knee osteoarthritis (OA) severity score, based on cartilage, osteophytes and meniscus (OA-COM), and to predict progression across different severity states using OA-COM as outcome and clinical variables as predictors. Methods Population-based knee pain cohort ag...

Background Purpose In response to the pandemic, some public health agencies recommend the wearing of surgical masks in indoor spaces including radiology common reporting rooms. We aim to demonstrate whether mask wearing may lead to increased errors incidence in radiology reports. Materials and Methods Our prospective studywas conveyed in 2 parts....

Purpose Assess the impact of 24/7/365 emergency trauma radiology (ETR) coverage on Emergency Department (ED) patient flow in an urban, quaternary-care teaching hospital. Methods Patient ED visit and imaging information were extracted from the hospital patient care information system for 2008 to 2018. An interrupted time-series approach with a comp...

Gout is the most common inflammatory arthropathy caused by the deposition of monosodium urate (MSU) crystals. The burden of gout is substantial with increasing prevalence of gout globally. The prevalence of Gout in the United States has increased by over 7% in the last two decades. Initially, it was believed that MSU crystal deposits occur only in...

Objectives To investigate machine learning classifiers and interpretable models using chest CT for detection of COVID-19 and differentiation from other pneumonias, interstitial lung disease (ILD) and normal CTs.Methods Our retrospective multi-institutional study obtained 2446 chest CTs from 16 institutions (including 1161 COVID-19 patients). Traini...

OBJECTIVE. The objective of our study was to provide insight on the diagnostic validity of cardiac CTA (CCTA) to identify obstructive coronary artery disease (CAD) and patients who require urgent intervention, compared with those who require same-admission coronary catheterization (CC), and to help elucidate the necessity of a 24/7 CCTA service. MA...

Dual-energy CT (DECT) provides insights into the material properties of tissues and can differentiate between tissues with similar attenuation on conventional single-energy imaging. In the conventional CT scanner, differences in the X-ray attenuation between adjacent structures are dependent on the atomic number of the materials involved, whereas i...

Chest X-ray imaging technology used for the early detection and screening of COVID-19 pneumonia is both accessible worldwide and affordable compared to other non-invasive technologies. Additionally, deep learning methods have recently shown remarkable results in detecting COVID-19 on chest X-rays, making it a promising screening technology for COVI...

Purpose: The RSNA expert consensus statement and CO-RADS reporting system assist radiologists in describing lung imaging findings in a standardized manner in patients under investigation for COVID-19 pneumonia and provide clarity in communication with other healthcare providers. We aim to compare diagnostic performance and inter-/intra-observer am...

Purpose To evaluate gender distribution in radiology professional society leadership positions. Our study intends to assess and compare the gender distribution among leadership roles and professional society committee memberships of the radiology societies and seek an understanding of potential associations between gender, academic research metrics...

OBJECTIVE. The purpose of this study was to analyze the contribution of dual-energy CT (DECT) to radiologist interpretation in the emergency department (ED) to determine whether recommendations for follow-up imaging decrease. MATERIALS AND METHODS. Reports of all DECT studies performed in an ED in 2016 were reviewed. A board-certified radiologist n...

Chest radiography is a critical tool in the early detection, management planning, and follow-up evaluation of COVID-19 pneumonia; however, in smaller clinics around the world, there is a shortage of radiologists to analyze large number of examinations especially performed during a pandemic. Limited availability of high-resolution computed tomograph...

Background: To evaluate whether knee osteoarthritis (OA) manifestations predict depression and anxiety using cross-sectional and longitudinal prediction models. Methods: A population-based cohort (n = 122) with knee pain, aged 40-79, was evaluated at baseline, 3 and 7 years. Baseline predictors were: age decade; sex; BMI ≥ 25; physical exam knee...

Purpose To assess the interobserver variability between chest radiologists in the interpretation of the Radiological Society of North America (RSNA) expert consensus statement reporting guidelines in patients with suspected coronavirus disease 2019 (COVID-19) pneumonia in a setting with limited reverse transcription polymerase chain reaction testin...

Purpose: Prospective radiology fellows utilize the internet to apply for radiology fellowship programs. The aim of this study was to analyze the online content of Canadian radiology fellowship websites. Methods: The content of all active Canadian radiology fellowship websites were evaluated using 30 criteria in the following domains: application...

Purpose: To present a method that automatically segments and quantifies abnormal CT patterns commonly present in coronavirus disease 2019 (COVID-19), namely ground glass opacities and consolidations. Materials and methods: In this retrospective study, the proposed method takes as input a non-contrasted chest CT and segments the lesions, lungs, a...

Purpose: To present a method that automatically segments and quantifies abnormal CT patterns commonly present in coronavirus disease 2019 (COVID-19), namely ground glass opacities and consolidations. Materials and Methods: In this retrospective study, the proposed method takes as input a non-contrasted chest CT and segments the lesions, lungs, and...

Gout is a common inflammatory arthritis that manifests as an aggregate of variably symptomatic monosodium urate crystals (MSU) in the joints and surrounding tissues in addition to multisystem involvement such as genitourinary and cardiovascular systems. In recent decades, there has been a documented increase in the prevalence and incidence of gout....

PurposePancreatic injury is associated with significant morbidity and mortality. Pancreatic lacerations can be challenging to identify as the pancreas is not scanned at peak enhancement in most trauma CT protocols. This study qualitatively and quantitively assessed pancreatic lacerations with virtual monoenergetic dual-energy CT (DE CT) to establis...

Coronavirus Disease 2019 (COVID-19) is the disease caused by the novel coronavirus officially named the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), declared as a pandemic by the World Health Organization on March 11, 2020. The COVID-19 pandemic presents an unprecedented challenge to emergency radiology practice. The continuity of...

Traumatic lower urinary tract injuries are uncommon and mainly occur in patients with severe trauma and multiple abdominopelvic injuries. In the presence of other substantial injuries, bladder and urethral injuries may be overlooked and cause significant morbidity and mortality. Therefore, it is important that radiologists are familiar with mechani...

Pregnancy is a special situation in a woman’s life, and emergencies arising in pregnant women require a particularly specialized approach. Due to the concerns of potential radiation risk to the developing fetus, imaging requiring ionizing radiation should be used judiciously. Ultrasound and magnetic resonance imaging play a substantial role in eval...

Purpose The internet is commonly employed by Radiology trainees to investigate and learn about potential fellowship programs. As a new and emerging subspecialty, Emergency Radiology requires strong internet presence and training program website content. This is vital to ensure good exposure of the fellowship programs to inform medical students, rad...

Emergency and trauma radiologists, emergency department’s physicians and nurses, researchers, departmental leaders, and health policymakers have attempted to discover efficient approaches to enhance the provision of quality patient care. There are increasing expectations for radiology practices to deliver a dedicated emergency radiology service pro...

Modern advances in the medical imaging layered onto sophisticated trauma resuscitation strategies in highly organized regionalized trauma systems have created a paradigm shift in the management of severely injured patients. Although immediate exploratory surgery to identify and control life-threatening injuries still has its place, accelerated imag...

Purpose: To present a method that automatically detects and quantifies abnormal tomographic patterns commonly present in COVID-19, namely Ground Glass Opacities (GGO) and consolidations. Given that high opacity abnormalities (i.e., consolidations) were shown to correlate with severe disease, the paper introduces two combined severity measures (Perc...

Purpose: To present a method that automatically segments and quantifies abnormal CT patterns commonly present in coronavirus disease 2019 (COVID-19), namely ground glass opacities and consolidations. Materials and methods: In this retrospective study, the proposed method takes as input a non-contrasted chest CT and segments the lesions, lungs, a...

Objective To evaluate gender and racial profiles of US academic radiology faculty. Materials and Methods This is a retrospective analysis of the American Association of Medical College database of radiology faculty members from 2006 to 2017 by academic rank, chair position, race or ethnicity, and gender. The data were described with annual proport...

Background Radiology trainees frequently use the Internet to research potential fellowship programs across all subspecialties. For a field like nuclear medicine, which has multiple training pathways, program websites can be an essential resource for potential applicants. This study aimed to analyze the online content of Canadian and American Nuclea...

Emergency trauma radiology, although a relatively new subspecialty of radiology, plays a critical role in both the diagnosis/triage of acutely ill patients, but even more important in providing leadership and taking the lead in the preparedness of imaging departments in dealing with novel highly infectious communicable diseases and mass casualties....

Traumatic injuries of the cervical carotid and vertebral arteries, collectively referred to as blunt cerebrovascular injury (BCVI), can result in significant patient morbidity and mortality, with one of the most feared outcomes being cerebrovascular ischemia. Systematic imaging-guided screening for BCVI aims for early detection to guide timely mana...

As forensic radiology sees an exponential gain in popularity, postmortem computed tomography (PMCT) is increasingly being used in the appropriate setting, either as preautopsy guidance or as part of complementary virtual autopsy protocol. Many articles have expounded the value it adds to forensic pathology in the general setting and the appropriate...

This review aims to examine the challenges facing radiologists interpreting trauma computed tomography (CT) images in this era of a changing approach to management of solid organ trauma. After reviewing the pearls and pitfalls of CT imaging protocols for detection of traumatic solid organ injuries, we describe the key changes in the 2018 American A...

Abdominal trauma, one of the leading causes of death under the age of 45, can be broadly classified into blunt and penetrating trauma, based on the mechanism of injury. Blunt abdominal trauma usually results from motor vehicle collisions, fall from heights, assaults, and sports and is more common than penetrating abdominal trauma, which is usually...

Traumatic diaphragmatic injury (TDI) is an underdiagnosed condition that has recently increased in prevalence due to its association with automobile collisions. The initial injury is often obscured by concurrent thoracic and abdominal injuries. Traumatic diaphragmatic injury itself is rarely lethal at initial presentation, however associated injuri...

Objective To offer an evidence-based account of the effect of 24/7/365 attending radiologist coverage on the turnaround time (TAT) of trauma-related radiographs finalized within 48 hours of exam completion, drawing data from an emergency radiology department of a tertiary care hospital in Vancouver, British Columbia. Materials and Methods This was...

Purpose In this systematic review and meta-analysis, we aimed to investigate the accuracy of dual-energy computed tomography (DECT) in the detection of acute pulmonary embolism (PE). Methods We searched Medline (via PubMed), EBSCO, Web of Science, Scopus, and the Cochrane Library for relevant published studies. We selected studies assessing the ac...

Objective To study the impact of 24/7/365 attending radiologist coverage on the turnaround time (TAT) of trauma and nontrauma cases in an emergency and trauma radiology department. Patients and Methods This was a retrospective chart review in which TAT of patients coming to the emergency department between 2 periods: (1) December 1, 2012, to Septe...

Objectives This study is an evaluation of the emergency department (ED) satisfaction with the current radiologic reporting system used at a major Northeastern academic medical center. The radiology reports are the main form of communication and usually the final product of any radiological investigation delivered to clinicians. The aim of this stud...

Traumatic cardiovascular injuries are only second to the central nervous system injuries as a cause of death in young adult population. Multidetector computed tomography is the gold standard diagnostic modality in patients with blunt or penetrating chest trauma and clinical suspicion of cardiac injury. The imaging spectrum of cardiac injuries inclu...

Purpose To assess the pattern of result communication that occurs between radiologists and referring physicians in the emergency department setting. Methods An institutional review board–approved prospective study was performed at a large academic medical center with 24/7 emergency radiology cover. Emergency radiologists logged information regardi...

Objectives To compare the scan acquisition time, radiation dose, subjective and objective image quality of two dual-source CT scanners (DSCT) for detection of acute pulmonary embolism.Methods Two hundred twenty-one scans performed on the 2nd-generation DSCT and 354 scans on the 3rd-generation DSCT were included in this large retrospective study. In...

The above article has an error in Figure 6 online (already correct in the PDF version) including the Graphical abstract figure. The original article has been corrected.

Objective To present a detailed exploratory data analysis for critically investigating the patterns in medical doctor (MD) to disposition time, pre and post 24/7/365 attending radiologist coverage, for patients presenting to an emergency department (ED). Materials and methods The process involved presenting several modeling techniques. To share an...

OBJECTIVE. Underrepresentation of women in the top hierarchy of academic medicine exists despite women comprising more than half of the medical school graduates and residency positions. The purpose of this study is to analyze and quantify the relationship of gender, research productivity, and career advancement in Canadian academic radiology depart...

Rationale and aim: In virtual dissection, three-dimensional computed tomography scans are viewed on a near-life size virtual dissection table and through touchscreen technology, students work together to manipulate the data to perform their dissection. The purpose of this study was to develop a Virtual Dissection Curriculum for first year medical...

Background: Radiology integration into medical anatomy courses is well established, but there is a paucity of literature on integrating virtual dissection into cadaveric dissection laboratories. Virtual dissection is the digital dissection of medical images on touchscreen anatomy visualization tables. The purpose of this pilot study was to investi...